Church World Service, the Protestant and Eastern Orthodox aid agency normally concerned with assisting victims of such natural disasters as massive droughts and hurricanes, now is raising funds to assist South African political prisoners.

The service agency of the National Council of Churches has appealed to U.S. churches for $100,000 for various types of assistance for South African political prisoners and their families.

So mamy opponents of the South African government policy of apartheid have been arrested in recent months that "we consider it very much like a natural disaster," said Willis H. Logan, assistant African director of the New York based organization.

Logan said money raised in the United States will be channeled through two South African agencies, the Asengeni Relief Fund and the Dependents Conference Fund. These funds were set up and supervised by the South African Council of Churches following the 1976 riots in Soweto.

According to Logan, money will be used "for legal defense fees, social services for families of prisioners such as helping members visit relatives who are in prison, and to some extent to help in the rehabilitation of persons after they are released from prison."

Church World Service launched its appeal for money in response to requests from Anglican Bishop Desmond Tutu of Johannesburg, general secretary of the South Africa Council of Churches.